UCLA

Objective

At-school substance use is associated with increased rates of violence and delinquency. However, whether at-school substance use is a useful marker for other serious health risks and whether this association varies by gender or substance is still unclear.

Methods

We analyzed data from the national 2011 Youth Risk Behaviors Survey of 15,698 ninth to 12th grade students. We used multivariate regressions controlling for age and race and evaluated whether at-school marijuana and alcohol users were more likely than out-of-school users to exhibit 9 serious health risks (exposure to intoxicated driving, fighting, carrying a weapon at school, substance use with intercourse, experiencing intimate partner violence, being forced to have intercourse, experiencing depression, suicidal ideation, and attempting suicide). We included interaction terms to determine whether this association varied by gender or substance.

Results

At-school alcohol and marijuana use were both associated with increased odds of all 9 serious health risks. The association between at-school substance use and fighting and being forced to have sex was greater for boys than for girls. Associations did not vary significantly by substance. Specificity of at-school substance use for serious health risks ranged from 0.93 to 0.96, and positive predictive values ranged from 0.23 to 0.69, well above the ranges for out-of-school use and nonuse.

Conclusions

Students found using alcohol or marijuana at school should be immediately and carefully screened for other serious health risks that pose significant present dangers; this might represent a critical opportunity to identify troubled youth.